diff --git a/local/patches/relibc/P3-sys-types-stdint-include.patch b/local/patches/relibc/P3-sys-types-stdint-include.patch
new file mode 100644
index 000000000..11bc36b48
--- /dev/null
+++ b/local/patches/relibc/P3-sys-types-stdint-include.patch
@@ -0,0 +1,8 @@
+--- a/src/header/sys_types_internal/cbindgen.toml
++++ b/src/header/sys_types_internal/cbindgen.toml
+@@ -1,4 +1,4 @@
+-sys_includes = ["stddef.h"]
++sys_includes = ["stddef.h", "stdint.h"]
+ # TODO: figure out how to export void* type
+ after_includes = """
+ 
diff --git a/recipes/core/relibc/P3-sys-types-stdint-include.patch b/recipes/core/relibc/P3-sys-types-stdint-include.patch
new file mode 120000
index 000000000..211e564a2
--- /dev/null
+++ b/recipes/core/relibc/P3-sys-types-stdint-include.patch
@@ -0,0 +1 @@
+../../../local/patches/relibc/P3-sys-types-stdint-include.patch
\ No newline at end of file
diff --git a/recipes/core/relibc/recipe.toml b/recipes/core/relibc/recipe.toml
index ddf19d19a..6f303b9a6 100644
--- a/recipes/core/relibc/recipe.toml
+++ b/recipes/core/relibc/recipe.toml
@@ -17,6 +17,11 @@ patches = [
     # timerfd: fix cbindgen.toml to generate C (not C++) headers
     "P3-timerfd-cbindgen-fix.patch",
 
+    # sys_types_internal: include stdint.h so uint32_t/int32_t are available to
+    # all downstream headers (signal.h, sys_signalfd.h, etc.) via the
+    # signal.h -> sys/types.h -> sys/types/internal.h include chain
+    "P3-sys-types-stdint-include.patch",
+
     # open_memstream: creates stdio/open_memstream.rs
     "P3-open-memstream-create.patch",
     # open_memstream: wires mod into stdio/mod.rs